The invention relates to an apparatus and method for printing onto lenticular media.
FIG. 1 shows a typical lenticular material 10. Such lenticular print material, as shown by the detail view in FIG. 1 has a series of parallel ridges 11 which act as cylindrical lenses formed on a front surface 12 of the material 10.
The material 10 is transparent and has a substantially planar rear surface 13. The parallel ridges 11 run the full length of the material 10 and are closely and evenly spaced from one another, and give rise to a special optical effect as will be further explained below.
Referring now to FIG. 2, there is shown in schematic form a set of three neighbouring ridges or lenses 111, 112, 113. Beneath each of the lenses 111 -113, there are laid strips forming parts of multiple images. In this instance, it is assumed that three images in total are viewable through the lenticular material. Parts A1, A2, A3 forming part of a first image A, parts B1, B2, B3 making up parts of a third image B and parts C1, C2, C3 making up parts of a third image C. Each of the parts of any given image A, B, C are equally spaced from one another and situated beneath corresponding portions of the lenses 111 -113. Because of the effect of the lenses, an observer looking at the lenticular material will effectively see a different image A, B or C dependent upon the viewing angle. In other words, by tilting the lenticular material, the viewer will see image A, B or C. These effects are very well known and such images tend to have a mostly recreational type valuexe2x80x94for instance, printing a composite image based on a sequence of time displaced images of a scene onto lenticular material in the abovedescribed fashion is often used to provide novelty items for children in which when the material is tilted, the illusion of movement is conveyed to the observer.
As will be understood from the above, in order to provide consistent effects, there are a number of prerequisites. These prerequisites are that each image be divided accurately into consistently sized strips. Those strips should have a width which enables an integer number of such strips to be placed beneath each lens, that integer number corresponding to the number of images to be presented to the viewer. Each such strip must be precisely aligned in relation to the corresponding cylindrical lens formed by the ridges 11 of the lenticular material.
One method for providing such an image is to simply print the composite image formed by the offset strips of the divided images directly onto paper and then to manually align the printed composite image with a lenticular substrate and glue the printed image to the substrate. This has the obvious disadvantage that manual alignment is subject to human error.
It is an aim of embodiments of the present invention to provide a simplified method and apparatus for printing onto lenticular material with automatic alignment.
According to a first aspect of the invention, there is provided a printer including a feed tray upon which material to be printed upon is placed, an elongate feed cylinder having a paper feeding surface for advancing material from the feed tray along an input path, printing means for printing upon the material and an output path for delivering printed material from the printing means, the feed cylinder having a paper feeding surface of the feed cylinder including a plurality of evenly spaced apart transversely arranged grooves, said grooves each being substantially perpendicular to a central longitudinal axis of rotation of said feed cylinder.
The output path may be the input path.
Preferably, said grooves each have an internal form arranged to match the form of individual lenses of lenticular material with which the feed cylinder is to be used. Lenticular material generally is formed of cylindrical lenses in which case the grooves preferably each have a substantially constant internal radius of curvature.
Preferably, the substantially constant internal radius of curvature of said grooves corresponds to a radius of curvature of corresponding cylindrical lenses of lenticular material which it is desired to use in conjunction with said printer.
Preferably, said evenly spaced apart transversely arranged grooves are spaced apart from one another in accordance with a given lenses per inch (lpi) designation of lenticular material to be used in conjunction with said printer.
Preferably, at boundary regions between adjacent transverse grooves, said grooves are separated from each other by regions of the feed cylinder which are of a substantially constant transverse circular cross-sectional diameter.
According to a second aspect of the invention, there is provided a method of printing directly onto lenticular material, the method comprising feeding lenticular material into a printer, the printer including a feed tray upon which material to be printed upon is placed, an elongate feed cylinder having a paper feeding surface for advancing material from the feed tray along an input path, printing means for printing upon the material, and an output path for delivering printed material from the printing means, the feed cylinder having a feeding surface including a plurality of evenly spaced apart transversely arranged grooves, said grooves each being substantially perpendicular to a central longitudinal axis of rotation of said feed cylinder, the method comprising:
(i) inputting lenticular material into the feed tray of the printer, said lenticular material being oriented such that lenses formed on a front side of the lenticular material are arranged to be channelled into the grooves formed in the feeding surface of the feed cylinder to align the material as the feed cylinder is rotated and to feed the material along the input path to the printing means;
(ii) using the printing means, printing a composite image onto a reverse side of the lenticular material using a composite image signal; and
(iii) delivering printed material from the printing means along the output path.
Preferably, there is performed the further step (iv) of applying a backing material to the reverse side of the lenticular material.
Preferably, said backing material comprises self-adhesive paper.
According to a third aspect of the invention, there is provided an elongate feed cylinder for a printer, a feeding surface of the feed cylinder being adapted for frictional engagement with a printing material and including a plurality of evenly spaced apart transversely arranged grooves, said grooves each being substantially perpendicular to a central longitudinal axis of rotation of said feed cylinder.
Preferably, said grooves each have an internal form arranged to match the form of individual lenses of lenticular material with which the feed cylinder is to be used. Lenticular material generally is formed of cylindrical lenses in which case the grooves preferably each have a substantially constant internal radius of curvature.
Preferably, said substantially constant internal radius of curvature of said grooves corresponds to a radius of curvature of corresponding cylindrical lenses on lenticular material which it is desired to use in conjunction with said feed cylinder.
Preferably, said evenly spaced apart transversely arranged grooves are spaced apart from one another in accordance with a given lenses per inch (lpi) designation of lenticular material to be used in conjunction with said feed cylinder.
Preferably, at transverse boundary regions between adjacent transverse grooves, said grooves are separated from each other by regions of the feed cylinder which are of a substantially constant transverse cross-sectional diameter.
Preferably, each of said boundary regions is of identical dimensions and each boundary region each occupies a given transverse area of the cylinder and is of a constant circular cross-sectional diameter.